Hi AllI had just started researching about how to create an electronic component tester using a microcontroller, and found the link to these devices as well as the original which suggest that somebody has already invented the wheel for me.I was wondering if there was much difference between the various ones available on fleabay at the moment, can anyone make any recommendations as to which ones/sellers are the most up to date?

I had just started researching about how to create an electronic component tester using a microcontroller, and found the link to these devices as well as the original which suggest that somebody has already invented the wheel for me.I was wondering if there was much difference between the various ones available on fleabay at the moment, can anyone make any recommendations as to which ones/sellers are the most up to date?

Actually you can buy any clone since they are all based on the same circuit. But most need a little fix as described in the official documentation. AFAIK there is no clone at ebay that includes all hardware extensions. Please see http://www.mikrocontroller.net/svnbrowser/transistortester/ for the documentation (English and German) and firmware updates.

this thread looks awesome. I build one of these based on Markus F. (2009) very early design (ATMEGA8/48). It serves me well. I think time has move on, may be I should upgrade. Just wonder which controller does this Chinese clone comes with? Cheapo AMEGA8 or they put in more expensive 128/328? Always a dilemma, to build or to buy?

I just did the bare minimum by removing the zener (which measured 2.03V instead of 2.5V), and adding 2 decoupling caps on the ATMEGA, I didn't do any other mods, I'm less concerned with battery life as with my amount of use the battery with lose most of its charge by self-discharge anyway

this thread looks awesome. I build one of these based on Markus F. (2009) very early design (ATMEGA8/48). It serves me well. I think time has move on, may be I should upgrade. Just wonder which controller does this Chinese clone comes with? Cheapo AMEGA8 or they put in more expensive 128/328? Always a dilemma, to build or to buy?

The clones we know about all got an ATmega168 but the 16k flash memory isn't enough to support all current firmware features. So I recommend to go for the ATmega328 (either replace the clone's 168 or build the tester yourself).

Yep, that's one of the common clones. But the firmware is a tad old by now. Karl-Heinz' current version is 1.08k and mine is 1.09m (no ESR, no hardware extensions, but a PWM tool).

That's the one I've also bought, but I made some changes to it: Apart from the decoupling capacitors, I changed the voltage regulator and the CPU (ATmega328), added a voltage reference (instead of the zener) and a 8 MHz crystal. Then I changed to the 1.08k version and works great.

Yep, that's one of the common clones. But the firmware is a tad old by now. Karl-Heinz' current version is 1.08k and mine is 1.09m (no ESR, no hardware extensions, but a PWM tool).[/quote]I guess asking the seller to tell you what the version is the only way to find out.

Do a search on ebay for "transistor tester esr" and you'll find lots of sellers. I would chose one with back-lit LCD. There also many revisions of the board I think that there are revisions 2.1, 2.2, 2.3, and 2.4 on the SMD version. I don't know what the difference between the revisions are. I'm sure that it is discussed on the forum:http://www.mikrocontroller.net/topic/248078.

Do a search on ebay for "transistor tester esr" and you'll find lots of sellers. I would chose one with back-lit LCD. There also many revisions of the board I think that there are revisions 2.1, 2.2, 2.3, and 2.4 on the SMD version. I don't know what the difference between the revisions are. I'm sure that it is discussed on the forum:http://www.mikrocontroller.net/topic/248078.

Problem with the url it has a period at the end so returns a 404 error.

The issue with all of these on fleabay is that they do not say what version they are for the ones I quickly scanned over.

That trailing dot is special (annoying) feature of this forum's software.

Aye.

I did not read every page of this thread so please forgive me if this has been answered already but if I own an Arduino Mega can I use it to do what these do by simply connecting the appropriate pins and loading up the proper software?

I also got a little lost with the different revision of the fw. What was added/removed in each revision? Is the HW exactly the same in all revisions?

I guess its all somewhere in the documentation, but a quick look only gave me partial answers. Never mind, I'm very happy with it, and fact I ordered one from eBay and spent no time in building it myself is even better as I don't have the time right now

I did not read every page of this thread so please forgive me if this has been answered already but if I own an Arduino Mega can I use it to do what these do by simply connecting the appropriate pins and loading up the proper software?

I did not read every page of this thread so please forgive me if this has been answered already but if I own an Arduino Mega can I use it to do what these do by simply connecting the appropriate pins and loading up the proper software?

I also got a little lost with the different revision of the fw. What was added/removed in each revision? Is the HW exactly the same in all revisions?

The firmware got additional features (can't remember them all :-) and tons of improvements. We keep everything compatible with the basic design, i.e. all hardware extensions are optional. If you got a very old hardware (Markus F.'s original design) you might need to apply some changes.

The need to go and check is exactly why I don't do that, who's got the time?!

Anyway, I'm happy with my unit. fw 1.05 might be a bit old, but it does what I need it to do. Resistors and capacitors are measured quite well with results no too far from my U1253A (actually very close to identical). Diodes Vf also about the same as I got at 6mA measurement in a test rig I once built (it had a temp chamber for temp-co measurement, and 6mA was used as this was the expected in circuit operation). I've measured some JFET's, BJT's, MOSFET's, everything seems to be good. Inductors are the only thing I can't confirm as I don't have an inductance meter (and the old time-constant measurement with the scope is too time consuming at the moment), but the values seem to be close to what's printed on the part so I guess its good as well.

I really only need it for ESR (to know if a cap is good or bad, the exact value is of no interest to me), for inductance (again, precision isn't very important for my current needs), and for transistor matching - it can do all this so its well worth the price.

So, best to buy one of those off of ebay then? Seems less costly but lacks freedom too I think.

The Transistor Tester isn't a development platform, it's a tool designed for a specific purpose. The Arduino lacks the complete power management which the Transistor Tester got (optimized for battery usage).

I really only need it for ESR (to know if a cap is good or bad, the exact value is of no interest to me), for inductance (again, precision isn't very important for my current needs), and for transistor matching - it can do all this so its well worth the price.

1.07k got an improved ESR measurement and 1.08k considers the leakage current of a BJT for hFE and fixes a problem with Germanium BJTs.